Method of making pipes for chimneys.



106. COMPOSITIONS,

I a COMING 0R PLASTIC @mss mm WW UNITED STATES PATENT OFFICE.

FRIEDRICH SCHOFER, OF WAIBLINGEN, NEAR. STUTTGART, GERMANY.

METHOD OF MAKING PIPES FOR CHIMNEYS.

1,112,725. specification of Letters n Patented Oct. 6, 1914.

No Drawing".

To all whom it may concern Be it known that I, FRIEDRICH SoHorEn, asubject of the German Emperor, residing at Waiblingen, near Stuttgart,in the German Empire, have invented certain new and useful Improvementsin Methods of Making Pipes for Chimneys and the like; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

Chimney pieces and pipe sockets for chimneys for conducting hot gasesare subject to very high duties with regard to their capacity ofwithstanding temperatures. It is not sufficient to employ a materialwhich is itself proof against heat; the respective parts must be madeso, that they will withstand the very sudden changes of temperatureoccurring in chimneys. They must allow of being alternately heated to avery high temperature and be again suddenly cooled down, without showingany cracks or fissures. Neither should steam affect them. It has beensuggested to use concrete, which is composed of cement and brokenbricks. Such a material is indeed better than any other kind ofconcrete. It will, however, nevertheless not be quite satisfactory, asit is impossible to obtain a suitable structure. The fine particles inthe brick material will render the concrete sensitive.

I have found that it is possible to obtain chimney tile free of alltension, and withstanding the changes of temperature if alcohol orspirit is added to the mixture of cement and crushed bricks or crushedfireclay, which has been slightly wetted with water, whereupon thematerial is shaken into the molds. This is done gradually and the moldsare then shaken in a Application filed February 17, 1913. Serial No.749,012.

vertical direction. The alcohol will prevent a too close settling.Besides it will, in evaporating, produce pores. This is my intention,for I have observed, that the pores render the material proof againstheat and free of tension. For instance I employ a mixture of 20 parts ofcement and 80 parts of c ignsl e d bricks, to which I add 6 parts ofwater and 5 parts of al c o h 9 l. The well mixed mass I then slowlyfill into the mold standing on a shaking table. A further improvement ofthe method according to the present invention consists in adding a smallamount of oil to the alcohol.

I claim:

1. The method of making fire-resisting cement articles, which comprisesmixing cement with crushed brick that has been ,wetted with a smallquantity of water, adding a; gohol to the mixture, molding the mass soobtained and allowing the cement to set.

2. The method of making fire-resisting cement articles, which comprisesmixing cement with burnt clay that has been wetted with a small quantityof water, adding to the mixture alcohol mixed with an oil, and moldingthe final mixture.

3. The method of making fire-resisting cement articles, which comprisesmixing cement and a comminuted burnt clay filler with about six parts ofwater and adding-to the mixture about five parts of an alcohol mixedwith a small quantity of oil, shaking the mixture down in molds andallowing it to set.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing witnesses.

FRIEDRICH SCHOFER.

Witnesses:

FRIDE KLABER, ERNEST ENTENMANN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents Washington, D. 0"

